In a prepared statement, the company said customer privacy is of the "utmost concern." Contrary to the hackers' claim that the site's "full delete" feature didn't actually delete user data from Ashley Madison's system, the company said the feature does remove all information related to a member's profile, include any messages and photos sent or received and billing information.

"The process involves a hard-delete of a requesting user's profile, including the removal of posted pictures and all messages sent to other system users' email boxes," the Toronto company said.

Details of the breach came to light Monday after a group of hackers called The Impact Team claimed responsibility for the hack. The group demanded that parent company Avid Life Media shut down Ashley Madison and a sister site, EstablishedMen.com.

As of Monday, Ashley Madison said the site had been secured and it had closed unauthorized access points.